From: Kees Cook Date: Mon, 27 Aug 2012 18:38:13 +0000 (-0700) Subject: Yama: handle 32-bit userspace prctl X-Git-Tag: v3.7-rc1~130^2~13 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=2e4930eb7c8fb20a39dfb5f8a8f80402710dcea8;p=linux.git Yama: handle 32-bit userspace prctl When running a 64-bit kernel and receiving prctls from a 32-bit userspace, the "-1" used as an unsigned long will end up being misdetected. The kernel is looking for 0xffffffffffffffff instead of 0xffffffff. Since prctl lacks a distinct compat interface, Yama needs to handle this translation itself. As such, support either value as meaning PR_SET_PTRACER_ANY, to avoid breaking the ABI for 64-bit. Signed-off-by: Kees Cook Acked-by: John Johansen Cc: stable@vger.kernel.org Signed-off-by: James Morris --- diff --git a/security/yama/yama_lsm.c b/security/yama/yama_lsm.c index 9ca43c1ea630..01d3b44b62c1 100644 --- a/security/yama/yama_lsm.c +++ b/security/yama/yama_lsm.c @@ -143,7 +143,7 @@ int yama_task_prctl(int option, unsigned long arg2, unsigned long arg3, if (arg2 == 0) { yama_ptracer_del(NULL, myself); rc = 0; - } else if (arg2 == PR_SET_PTRACER_ANY) { + } else if (arg2 == PR_SET_PTRACER_ANY || (int)arg2 == -1) { rc = yama_ptracer_add(NULL, myself); } else { struct task_struct *tracer;